The present invention relates to a device for the storage of flat, flexible data cards in a manner which allows easy access and retrieval. In particular, the invention relates to the storage of microfiche in a panel having multiple individual pockets, and to the method of manufacture of such a panel.
The storage of data on microfiche has, in recent years, become increasingly popular. As a result, various means have been devised for the storage of microfiche, and such devices have met with varying degrees of success. One particularly popular type of storage device is that which is commonly known as a panel file. Such panel files generally consist of a plurality of panels or frames, each having multiple individual pockets for the placement of microfiche, with the panels being adaptable for storage in a ring binder or a rotary stand.
The utility of such panel files, however, has been limited to some extent by a number of disadvantages. For example, one common type of panel file comprises a number of vertically spaced overlapping solid panes of material arranged to form a vertically disposed overlapping series of pockets. The primary disadvantage of such a panel file is inherent in the fact that such a construction provides a relatively thick and bulky panel, thus limiting the number of such panels which can be placed in a ring binder or on a rotary stand. Furthermore, panels constructed in this manner tend to constrict the microfiche progressively more tightly as more and more microfiche elements are inserted in the pockets. This feature makes insertion and removal of microfiche elements increasingly difficult as the panel is filled towards it ultimate capacity, thereby making its use more cumbersome and also increasing the probability of scratching or marring the microfiche data elements during the insertion or removal process. Furthermore, the formation of pockets which are constructed with solid panes of material front and back tends to trap dirt and abrasive material which harm delicate microfiche during the insertion or removal process.
Two variations of another type of panel file are disclosed in U.S. Pat. No. 2,959,897 to Mazur and U.S. Pat. No. 4,055,010 to Fridlund et al. A feature which is common to both of these designs is the formation of pocket entrances by means of cutting horizontal slits into a sheet of material. While such a feature allows the construction of a thinner, less bulky panel file, this result is accomplished at the expense of structural strength. Thus, panel files constructed in accordance with the teachings of Mazur or Fridlund patents may exhibit a tendency to tear, and therefore lack durability. In addition, the failure of these panels to provide an entrance channel bounded by overlapping sheets makes insertion of data elements difficult.
Hence, there has been a need for a file panel which combines strength and durability with a thin profile and easy data element insertion and that is not prone to excessively tight packing and scratching of the microfiche as the file is filled to capacity.